| 摘要 |
Procedure for preparing thermomechanical pulp from wood chips, wherein the chip flow is conducted from a storage reservoir under normal pressure through a first lock feeder into a pressurized steaming chamber, where the chips stay for a few minutes and are heated to an optimum temperature of 100 DEG to 125 DEG C., and from the steaming chamber through a second lock feeder to a feed means which supplies the chips into an enclosed hot refiner. In the procedure the steam discharging from the throat of the refiner against the chip flow is utilized for heating the chips in the steaming chamber, and the steam separated from the mechanical pulp is led off for use elsewhere. The steam utilized for heating the chips is conducted in complete counter-current fashion with regard to the chip flow, that is through the feed means, second lock feeder, steaming chamber, first lock feeder and reservoir under normal pressure into the open atmosphere, and the refining of the chips is carried out at a substantially higher temperature than the heating of the chips preferably not less than 135 DEG .
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